Scientists found, over a period of 30 years, the more nuts people ate, the less likely they were to die.
A daily handful of nuts cut death rates from any cause by a fifth, reduced those related to heart disease by nearly 30 per cent, and lowered the chances of dying from cancer by 11 per cent.
Regular nut-eaters also enjoyed the added benefit of being slimmer than nut dodgers.
The findings, drawing on data on almost 120,000 American men and women, suggests that nut-lovers who adopt squirrel-like eating habits may have solved the problem of how to snack and stay healthy.
“The most obvious benefit was a reduction of 29 per cent in deaths from heart disease – the major killer of people in America,” said Dr Charles Fuchs, from the Dana-Farber Cancer Institute in Boston, who led the study published in the New England Journal of Medicine.
“But we also saw a significant reduction – 11 per cent – in the risk of dying from cancer.”
Nut-eaters tend to be more health-conscious than average members of the public.
The study found they were leaner, less likely to smoke, and more likely to exercise, take vitamin supplements, and consume fruit and vegetables.
But all these factors were taken into account by the researchers, who used statistical techniques to isolate the independent association between nut consumption and mortality.
“In all these analyses, the more nuts people ate, the less likely they were to die over the 30-year follow-up period,” said co-author Dr Ying Bao, from Brigham and Women’s Hospital in Boston.
Death rates from all causes were reduced by 11 per cent in people who ate nuts once a week, 13 per cent in those who ate them two to four times a week, and 15 per cent when nuts were consumed five to six times a week.
Individuals with a daily nut “habit” were 20 per cent less likely to die over three decades.
The researchers examined health data from two large lifestyle studies conducted in the US among health workers: the Nurses’ Health Study and the Health Professionals’ Follow-up Study.
Participants in both filled in detailed food questionnaires every two to four years and the progress of their health was monitored.
As part of the research, they were asked to estimate how often they consumed nuts in a serving size of one ounce – equivalent to a handful.
Although the study was unable to single out the “healthiest” nut, it showed that the effect on death rates was similar for “tree nuts”, such as walnuts, hazelnuts, cashews, almonds, Brazil nuts, pecans and pistachios, and peanuts, which are not true nuts but beans which grow from roots.
Several studies have linked nut consumption with health benefits, such as reducing the risk of heart disease, diabetes and bowel cancer.
But this was the first large-scale study of the impact of nut consumption on mortality, the authors said.
The scientists, who received a research grant from the International Tree Nut Council as well as the US National Institutes of Health, said it was not possible to prove a causal link between eating nuts and living longer.
But they wrote: “Our data are consistent with a wealth of existing observational and clinical trial data in supporting the health benefits of nut consumption for many chronic diseases.
“In addition, nutrients in nuts such as unsaturated fatty acids, high-quality protein, fibre, vitamins and minerals may confer cardioprotective, anti-carcinogenic, anti-inflammatory, and antioxidant properties.”